Olawoyin Olufunmilayo Esther — data analyst, Lagos · remote

Every dataset has a story. I find it — and prove it.

Physics graduate turned analyst. I clean stubborn data, interrogate it with Excel, SQL, R, and Python, and hand back findings that non-technical people can act on — from supermarket floors to public health policy.

Read the caseworkGet in touch
5,000 student records modeled in R500 public-health reports analyzed6 policy recommendations delivered₦153,500 revenue tracked automatically4-panel Power BI-style dashboards in ExcelExcel · SQL · R · Python · Power BI

Selected work

Four investigations,
told by the numbers.

All projects
01

Public health · IDSS2 dataset

The sixteen-point gap nobody had mapped

Five diseases, 500 case reports, and a recovery-rate spread wide enough to be a policy problem — not a medical one.

EDADemographic analysisPolicy reportingExcel
02

Education · 5,000 student records

The model that was too perfect

A regression came back with R² = 1.000. Instead of celebrating, I went looking for the leak — and found it.

RMultiple regressionHypothesis testingEDA
03

Retail analytics · synthetic sales data

The weekend effect, and the Tuesday problem

A four-panel dashboard that explained why revenue swung across the week — and what to do about the mid-week slump.

ExcelDashboard designFeature engineeringPivotTables
04

Small business · spreadsheet engineering

A ledger that does its own math

A formula-driven sales log that turns a shop owner's daily entries into live revenue and profit — with no manual arithmetic anywhere.

ExcelAdvanced formulasAutomationPower Query

The toolkit

The right tool,
not the loudest one.

Sometimes the answer is a regression in R. Sometimes it’s a ruthlessly well-built spreadsheet. Knowing which is half the job.

See the full stack

Data Analysis & Statistics

Exploratory Data AnalysisStatistical ModelingHypothesis TestingRegression Analysis

Data Visualization

Power BIR — ggplot2R — tidyverseExcel Charts

Spreadsheet Engineering

Advanced FormulasPivotTablesPower QueryPower Pivot

Databases & Querying

SQL — JoinsSQL — AggregationsSQL — Subqueries

Programming Languages

RPython

Core competencies

Data Cleaning & PreparationTrend & Demographic AnalysisInteractive Dashboard BuildingExecutive Reporting & Presentations

From the notebook

Writing about the work.

All posts
2 min read

The model that was too perfect

My regression came back with R² = 1.000. That is not a good result — it is a confession. Here is how I found the leak.

RRegressionData quality
2 min read

Your worst sales day is Tuesday. Here's what to do about it.

Weekend peaks are obvious. The money is in understanding the trough — and one engineered column is all it takes to see it.

ExcelRetailDashboards
2 min read

Excel is not a lesser tool

There's a snobbery in analytics that says real work happens in Python. I've watched a well-built spreadsheet change how a business runs.

ExcelAutomationSmall business

The next chapter

Your data already knows the answer. Let’s go ask it.

Open to data analyst roles and freelance analysis — remote or Lagos. Bring the messy spreadsheet; that’s the fun part.

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